In a case where a cabinet, a rack device, or the like on which an electronic device is mounted is assembled, a rail member is fastened between standing pillar members in a horizontal manner. Conventionally, there is proposed an improvement in fastening the pillar member and the rail member (Japanese National Publication of International Patent Application No. 2007-507862). Also, there is proposed a board anchor that may be used for the fastening the pillar member and the rail member (Japanese Laid-open Utility Model Publication No. 1-124411).
Incidentally, in a case where the pillar member and the rail member are fastened to each other, a head portion of a screw used for the fastening is typically located at the outside of the pillar member. For example, the rail member is brought into pressure contact with a wall surface of the pillar member, a male screw is inserted from a rear side of the wall surface with which the rail member is brought into contact, that is, from the outside (front side) of the pillar member, and the head portion of the male screw is rotated to fasten both members. In such a way, when the head portion of the screw is located at the outside of the pillar member, it may be difficult for an operator to solely fasten the pillar member and the rail member. In order for the operator to solely fasten both members, the screw has to be inserted from the outside of the pillar member and the head portion has to be rotated and tightened with the rail member held to be brought into contact with the pillar member. It is very difficult to perform such an operation. Thus, operators make a pair to typically fasten the pillar member and the rail member. There is such a problem not only in a fastening operation of the pillar member and the rail member but also in a fastening operation of plural members.